ROTARY MUD DRILLING
Rotary Mud Drilling (RMD) is the most commonly used method of drilling. In direct RMD water or water with additives/mud is pumped down a drill pipe out through ports or jets in the drill bit. The fluid then flows up the space between the hole and drill pipe, known as the annular space.
The fluid carries the drill cuttings in suspension to the surface of the borehole. At the surface the fluid is channelled into settling pits or tanks where most of the cuttings settle out.
Clean drill fluid is then picked up from the opposite end of the settling area. The drilling fluid is then re-circulated down the hole, the process is repeated until the drilling is complete.
Advantages of Rotary Mud Drilling
- It is the least expensive drilling method
- Fastest drilling method through soft formations e.g. sand, clay layers and soft rock
- The hydrostatic pressure of the drilling fluid will keep a otherwise collapsing soft formation open
Disadvantages of Rotary Mud Drilling
- Not recommended for soil or site investigation drilling due to cross over of soil samples
- Cannot penetrate hard rock formations
to learn more visit www.boreholemachine.co.za or call 0860 448367